Allow pages on the OSX app launcher to be turned while dragging.

ui/app_list/cocoa/app_list_pager_view.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_APP_LIST_COCOA_APP_LIST_PAGER_VIEW_H_
 #define UI_APP_LIST_COCOA_APP_LIST_PAGER_VIEW_H_
 
 #import <Cocoa/Cocoa.h>
 
 #import "ui/base/cocoa/tracking_area.h"
@@ skipping 16 matching lines @@
 // highlight that mirrors the visible portion of the page.
 @interface AppListPagerView : NSSegmentedControl {
  @private
   // Used to auto-select a segment on hover.
   ui::ScopedCrTrackingArea trackingArea_;
 
   // The segment currently highlighted with a mouse hover, or -1 for none.
   NSInteger hoveredSegment_;
 }
 
+// Returns -1 if |locationInWindow| is not over a segment. Otherwise returns the
+// segment index and highlights it.
+- (NSInteger)findAndHighlightSegmentAtLocation:(NSPoint)locationInWindow;
+
 @end
 
 #endif  // UI_APP_LIST_COCOA_APP_LIST_PAGER_VIEW_H_